• Journal of Korean Society for Atmospheric Environment
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• v.27 no.1
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• pp.50-62
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• 2011

Temporal trends and spatial distributions of ozone concentrations in Pohang were investigated using data measured at 4 air quality monitoring stations (i.e., Daedo, Jukdo, Jangheung, and Desong) during 2002-2006. The monthly mean ozone concentrations were highest during April and June and decreased during July and August, which follows the typical trend in the Northeast Asia region. The high springtime ozone concentration might have been strongly influenced by the enhanced photochemical ozone production of accumulated precursors during the winter under increased solar radiations. In July and August, ozone levels were decreased by frequent and severe precipitation that caused lower mean monthly solar radiation and efficient wash-out of ozone precursors. This suggests that precipitation is extremely beneficial in the aspect of ozone pollution control. High ozone concentrations exceeding 80ppb dominantly occurred in May and June during the late afternoon between 16:00~17:00. Ozone concentrations were higher in Jangheung and Daesong relative to Daedo and Jukdo, whereas total oxidants $(O_3+NO_2)$ were higher in Jangheung and Daedo. In the suburban area of Daesong, ozone concentrations seem to be considerably higher than those in urban sites of Daedo and Jukdo due to lower ozone loss by NO titration with lower local NO level.

• Journal of Preventive Medicine and Public Health
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• v.32 no.2
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• pp.191-199
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• 1999

Objectives: To examine the relationship between air pollution exposure and mortality in Seoul for the years of 1991-1995, Methods: Daily counts of death were analyzed by general additive Poisson model, with adjustment for effects of secular trend, seasonal factor, day of the week, heat wave, temperature, and humidity. Pollution variables were ozone, nitrogen dioxide, total suspended particles(TSP), and sulfur dioxide. Results: Daily death counts were associated with ozone(1 day before), nitrogen dioxide(1 day before), TSP(2 days before), sulfur dioxide(2 days before). The association with ozone was most statisfically significant and independent of other air pollutants. Increase of 100 ppb in ozone was associated with 0%(95% Cl= 2%-10%) increase in the daily number of death, This effect was greater in persons aged 65 and older. The relative risks of death from respiratory disease and cardiovascular disease were greater than for all-cause mortality in each pollutant. After ozone level exceeds 25 ppb, the dose-response relationship between mortality and ozone was almost linear. However, the effect of TSP, sulfur dioxide, and nitrogen dioxide on mortality might be confounded with each other. Conclusion: Daily variations in air pollution within the range currently occurring in Seoul might have an adverse effect on daily mortality.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2005.11a
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• pp.211-213
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• 2005

• Particle and aerosol research
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• v.7 no.1
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• pp.1-8
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• 2011

In this study, the formation of nanoparticles by a reaction of ozone with the volatile organic compounds(VOCs) emitted from a commercial home cleaner liquid was investigated using a $1-m^3$ reaction chamber($1{\times}1{\times}1m$). The home cleaner liquid was found to contain many VOCs, particularly terpenes. Some of these VOCs are known to readily react with ozone, forming indoor secondary pollutants. The correlation of particle concentration and reacted ozone concentration was examined with injections of three different ozone concentrations; 50, 100 and 200 ppb. The secondary nanoparticles were formed faster, with their numbers and mass concentrations becoming higher on increasing the concentration of ozone injected.

• Journal of Environmental Science International
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• v.11 no.12
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• pp.1253-1259
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• 2002

This study analyzes the surface ozone, NO and $NO_2$ concentration data from 1997 to 1999 in Daegu. It investigates effect on precursor during high-ozone episode days. The high-ozone episode is defined when a daily maximum ozone concentration is higher than 100 ppb(ambient air quality standard of Korea) in at least one station among six air quality monitoring stations. The frequency of episodes is 13 days(33 hours). The frequency is the highest in May and September, and the area with the highest frequency is Nowondong and Manchondong. The average value of daily maximum ozone concentration with high ozone episode is 81.6 ppb, and that of 8-hour average ozone concentration is 58.6 ppb. It means that ozone pollution is continuous and wide-ranging in Daegu. The daily variation of NO, $NO_2$ and $O_3$ in high-ozone episodes are inversely proportional one another. Nowondong an industrial area, is affected by pollutants that are emitted from the primary sources, while Manchondong a residential area, is affected by the advection of $O_3$ or by the primary pollutants like VOCs.

• KIEAE Journal
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• v.12 no.6
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• pp.93-98
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• 2012

The concerns on high ozone concentration phenomenon is significantly growing in Seoul metropolitan area including the industry complex area, like Shiwha Banwol area. The aims of this research is the analysis of relationship between high concentrations of $O_3$ and solar radiation parameters in atmosphere. The understanding of the effects of solar radiation intensity, humidity, high air temperature on ozone concentration in a day is very useful to provide a direction for reducing of the high ozone concentration to a local government or a metropolitan government. The correlation analysis between maximum ozone concentration and various meteorological parameters in 2009 - 2011 carried out using IBM's SPSS program. The results showed that the mean correlations coefficient (R) between daily Ozone maximum and solar radiation resulted R = 0.64 during 2011. May - September in 10 air pollution stations. In case of correlations between daily ozone maximum and relative humidity showed negative correlation R = -0.61. The correlation analysis with mean air temperature during 1-3 PM resulted R = 0.29. This low correlation coefficient could be corrected by using of categorized data of ozone concentration. The daily maximum ozone concentration is more dependent on peak solar radiation and high air temperature during 1-3 PM than its simple daily maximum values. The results of this research would be used to develop the high ozone alert system around Seoul metropolitan area. This correlation analysis could be partially integrated to prediction of ozone peak concentration in connection with other methods like classification and regression tree(CART).

• Journal of Korean Society of Forest Science
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• v.109 no.1
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• pp.50-61
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• 2020

Street trees are very important to urban environments as they can alleviate air pollution. However, when ozone is absorbed through the stomata, it can induce the formation of free radicals inside the tree, negatively affecting the vegetation. The present study investigated the Air Pollution Tolerance Index (APTI) of four major street tree species: Prunus yedoensis, Zelkova serrata, Chionanthus retusus, and Pinus densiflora. Two-year-old seedlings were placed in a phytotron and fumigated with 100 nL·L^-1 (ppb) ozone for 4 weeks, following which the ascorbic acid contents, chlorophyll contents, leaf pHs, and relative water contents were measured. There was no significant difference in the APTI of Prunus yedoensis and Zelkova serrata between the ozone and control treatments. By contrast, the ozone treatment caused the APTI of Chionanthus retusus to increase and that of Pinus densiflora to decrease compared with the respective controls. These results suggest that the APTI of these tree species exhibit very different responses to ozone. Therefore, more detailed research should be conducted on a range of species in the future.

• Journal of Korean Society of Forest Science
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• v.89 no.1
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• pp.65-76
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• 2000

Lichen flora of 'Backwoon' mountain, Korea, was investigated during the summer of 1998 and 1999 to screen out lichen species which can be used as a biomonitor for atmospheric ozone. The identified foliose or fructicose lichens in the area were classified into 9 families, 20 genera and 34 species. The dominant lichen species in the area were found to be Leptogium sp., Parmelia sp., Parmotrema sp., Phaeophyscia sp. and Cladonia sp. It was also found that lichen species showing a wide range of sensitiveness to air pollution were distributed in 'Backwoon' mountain. The Parmotrema austrosinense, P. tinctorum, Certrelia braunsiana and Ramalina yasudae collected in the area were exposed to ozone at the level of 200ppb, 8hr/day in controlled growth chamber for 2 weeks. Malondialdehyde(MDA), hydroperoxy conjugated dienes(HPCD), soluble protein content and OD435nm/OD415nm ratio for phaeophytinization of chlorophyll were measured and a pollution index(PI) was calculated for each lichen. Ozone exposure severely damaged to the lichens in the order of P. austrosinense>P. tinctorum>C. braunsiana>R. yasudae. P. austrosinens easily identified and widely distributed in Korea is likely to be a very useful biomonitor of air pollution, especially for ozone. These results indicate that Korean lichen species can be used as a biomonitor for air pollution to evaluate air quality contaminated with ozone.

• Journal of Preventive Medicine and Public Health
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• v.39 no.1
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• pp.81-86
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• 2006

Background: A number of studies have reported associations between the ambient air pollution concentrations and various health outcomes. Especially, ozone is well known for primary risk factor of asthma attacks. The results of a recent study indicate that the size of the effect on health outcomes due to air pollution varied according to several conditions, including age, gender, race and the socioeconomic status. Therefore, this study was conducted to examine the associations of ozone with the childhood asthma hospitalizations as stratified by the socioeconomic status (SES) at the community level in Seoul, Korea, 2002. Methods: SES at aggregated levels was measured on the basis of average regional health-insurance rate per citizen in the area. We applied the generalized additive model to analyze the effect of ozone on asthma after controlling for the potential confounding variables that were capable of influencing the results. Results: Our analysis showed that the number of children who were hospitalized for asthma increased as the SES of the residence area decreased. The estimated relative risks of hospitalization for asthma, as stratified by the SES of the community level, were 1.12 (95% confidence interval 1.00-1.25) in districts with the highest SES levels, 1.24 (95% CI=1.08-1.43) within the moderate SES levels, and 1.32 (95% CI=1.11-1.58) in the districts with the lowest SES levels. Conclusions: Our analysis showed that exposure to air pollution did not equally affect the health status of individuals. This suggests that not only the biological-sensitivity markers, but also the SES of the subjects should be considered as potentially confounding factors.

• Journal of Korean Society of Forest Science
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• v.97 no.5
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• pp.552-554
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• 2008

Acer palmatum was selected and its responses to elevated ozone were subsequently measured during growing periods. Ozone concentration of this study was compared to the calculated AOT40 value. A. palmatum had significantly many but small stomata size to the ozone stress. The length of stomata of A. palmatum was reduced from 5.6 to $5.0{\mu}m$ to the ozone exposure. However, the number of stomata (density) was increased from 102 to 131 in the $500{\times}500{\mu}m$ leaf area.